Method of coating wire



June 5, 1934. c JOHNSQN 1,961,667

METHOD OF COATING WIRE Filed Dec. 10, 1950 Fig. l.

Patented June 5, 1934 UNITED STATES PATENT. OFFIE 1.901.: V sin-moo orcourse ms Charles D. Johnson, Worcester, Mau 'asslgnor to Johnson Steel8: Wire Company. Inc., Worcester, Mass, a corporation of MassachusettsApplication December 10 1930, Serial No. 501,239 1 Claim. (01. arr-cs3)This invention relates to the production or metal-coated wire andparticularlyto a process of producing metal-coated wire which isstraight.

One common method of coating wire is to pass.

I washing baths during the coating operation and wire.

in passing through each washing bath the wire is taken over supportingrolls and under holddown rolls.

This passing of the wire over the supporting rolls and under thehold-down rolls as it passes through the various baths bends the wireand. tends to put into it a permanent set so that after having passedthrough the several baths the wire is not entirely straight.

For some purposes it is highly desirable that the coated wire should beas straight as possible and while the coated wire may be given thedesired straightness by passing it through a wirestraightening deviceafter the coating operation has been completed, yet the action of thewirestraightening device on the coated wire is very apt to injure themetal coating either by scratching it or otherwise so that while a wirewhich is straightened after being coated may meet the requirements sofar as straightness is concerned it does not always meet requirements asregards the character of the coating.

It is one of the objects of the present invention to provide ametal-coated wire which is straight and which is provided with a coatingthat has not been injured by the wire-straightening devices. Inaccordance with the present invention I take the uncoated wire and passit through a wire-straightening machine of some suitable type thereby tostraighten the wire and the wire thus straightened is then subjected tothe coating operation while maintaining the wire in a straight conditionand without bending the As a result the wire comes through the coatingapparatus ina perfectly straight condition and with a coating whichhasnot been in-' jured or damaged by the wire-straightening device becauseof the fact that the coating is applied after the wire is straightened.

In order to give an understanding of the invention I have illustrated inthe drawing somewhat diagrammatically difierent ways in which myimproved process may be carried out.

Fig. 1 is a diagrammatic view illustrating one manner of practising myinvention Fig. 2 is a sectional perspective view illustrating the mannerin which the wire is subjected to the action of the plating materialwhile maintaining the wire straight;

Fig. 3 is an enlarged sectional view showing the way of cleaning thewire straight;

Fig. 4 is-a diagrammatic view illustrating a diiferent manner ofsubjecting the wire to the plating bath and washing bath whilemaintaining it straight.

In the drawing, 1 indicates the wire which is to be straightened andplated or coated. In

carrying out my invention 1 first subject the wire to the action of awire-straightening machine thereby straightening the wire, and then Wplate or metal-coat the straightened wire while maintaining it in itsstraight condition.

The wire to be straightened and plated is shown as taken from a reel 2and it is straightened by passing it through a wire-straighteningmachine 3. This wire-straightening machine may be of any suitable orusual construction, that herein shown being ot the type known as arotary wire-straightening machine. The wire- -straightening machine isillustrated diagrammatically in the drawing since its construction andoperation is well known to those skilled in the art. The wire comes fromthe straightening machine 3 in a straight condition and in ac cordancewith my invention it is maintained in its straight condition while it isbeing plated.

As a preliminarystep to the actual plating of the wire the latter isfrequently cleaned in some suitable way so that it will be free fromgrease,

oil, lime or other foreign matter when it is subjected to the platingoperation. One common way of thus cleaning the wire is to subject it tothe action of a suitable acid.

Fig. 1 of the drawing shows not only a means for cleaning the wire bysubjecting it to an acid bath but also shows abrasive cleaning meanswhich subjects the wire to an abrasive action to assist the cleaningoperation. This abrasive or scouring action on the wire may beaccomplished by drawing the wire through a bed of granular abrasivematerial. Such a bed is illustrated diagrammatically at 55 and it isshown as situated between the reel 2 and the straightening machine 3 sothat as the wire is drawn from the reel to the straightening machine itwill be.

while maintaining it subjected to the abrasive or scouring action whichwill be effective in removing lime or similar foreign matter from thesurface of the wire and will have a scouring action on the wire.

The cleaning of the wire by the action of acid thereon may be done by asuitable apparatus which is indicated generally at 4. This consists of atrough 5 for containing acid, the ends 6 of which may be formed ofrubber or some other acid-resistant material which has holes thereinthrough which the wire or wires pass.

Means are provided for maintaining the trough 5 filled with acid so thatas the wire passes from one end to the other thereof it will besubmerged in the acid bath. As herein illustrated the trough 5 issupported above a vat or tank 7 containing acid and the bottom of thetrough has one or more openings 8 beneath each of which is situated anair jet nozzle 9. Each air jet nozzle 9 blows air up through the opening8 and the rising current of air carries with it acid so that the trough5 will be kept filled with acid. This trough is of less length than thevat or tank 7 and, of course, there will be a leakage of acid throughthe wire-receiving holes in the end walls 6 but such leakage will becompensated for by the acid which is carried from the tank 7 into thetrough 5 by means of the air jet. In passing through the trough 5 thewire is maintained in its straightened condition and with thisconstruction the wire will be subjected to the necessary acid treatmentfor cleaning it while it is still maintained in a straight condition.

After the wire is taken from the cleaning bath it is subjected to theplating operation and this is done while the wire is maintained in astraight condition. One way of thus plating the wire while it ismaintained straight is by flowing the plating material over the wire asit is moved along and while it is still maintained in a straightcondition. Various devices for accomplishing this may be used withoutdeparting from the invention.

In Figs. 1 and 2 I have shown a device 16 by which the wire is passedabove a vat or tank containing the plating material and a continualstream of plating material is forced upwardly onto the wire as it movesalong. 10 indicates a tank or container which is adapted to hold theplating material. At the upper end of this tank is a trough-like member11 having a relatively narrow throat 12 and extending longitudinally ofthe trough is a perforated pipe 13 which is connected to a source ofcompressed air. The level of the plating material in the tank 10 will beso maintained that the trough 11 is partially submerged, the throat 12of the trough, however, being above the level of the plating material.This trough is formed with two wings 14 extending laterally from eachside of the throat 12, these wings being situated below but closelyadjacent to the wire 1 as it passes over the tank.

The compressed air which is delivered to the pipe 13 will cause theliquid plating material in the trough 11 to bubble up through the throat12 thus forming a sort of fountain and as the wire is passing over thetrough closely adjacent the throat the wire will pass through thisfountain of plating material, during which a deposit is formed on thewire thereby plating it. The plating material which has been forcedupwardly through the throat 12 of the trough flows over the wings 14 andback into the tank 10 again.

I have also shown a perforated pipe 15 in the bottom of the tank 10through which compressed air is delivered. This air bubbles up throughthe mass of plating material in the tank 10 and thus keeps it thoroughlyagitated and properly mixed.

The character of the plating material which is used for plating orcoating the wire may vary depending on the character of the coated wirewhich it is desired to produce. This coating material may be in the formof an aqueous coating solution, such as a mixture of blue vitriol andsuitable acid, which will result in applying a coppercoating to thewire, or the aqueous solution may have the proper characteristic toapply a brass coating to the wire or the wire coating material may be ofthe proper character to apply a coating of tin or zinc or any otherdesired metal to the wire.

Moreover, it may be desirable to subject the wire to more than one bathof plating material and if this is necessary to secure a coating of thedesired character then additional devices such as indicated at 16 andsimilar to that above described may be employed for subjecting the wireto a further bath of plating material.

In some plating operations it is customary towash the wire before andafter each plating operation and with my invention I provide means forthus washing the wire without bending the wire and while it is stillmaintained in a straight condition. As shown in Fig. 1 the wire issubjected to two plating operations, one through the medium of theplating device 16 and again through the medium of a somewhat similarplating device indicated at 19. The plating device 19 is similar to theplating device 16 except that the device 19 has two troughs 11 insteadof one so that in passing over the device 19 the wire will be subjectedto a double plating action.

In Fig. 1 I have shown one wire-washing device 17 between the acid bathand the plating device 16, another washing device 18 between the twoplating devices 16 and 19 and a third washing device 51 by which thewater is washed after it comes from the second plating device 19.

These wire-washing devices may conveniently be constructed similar tothe plating devices in that they are provided with means for creating asort of fountain of water through which the wire is drawn and whichserves to wash the wire while it is still maintained in a straightcondition. The washing device 17, for instance, is illustrated ascomprising a tank 20 containing water in the upper end of which is atrough-like element 21 having the narrow throat 22. The trough ispartially submerged in the water in the tank 20 but the throat 22 isabove the level of the water. Situated in the bottom of the trough is aperforated pipe 23 through which air under pressure is delivered.

The air bubbles up through the water in the trough carrying a sort offountain of water up through the throat 12 through which fountain thewire is drawn. 1

24 indicate wipers of any usual construction by which the wire is wipedafter it is subjected to each bath.

In producing some kinds of plated wire it is desirable to dry the wirerapidly and without subjecting it unnecessarily to oxidization as soonas the wire comes from the last water bath. I have herein shown a drier26 suitable for this purpose and which is in the form of a bed 27 ofheated granular material through which the wire is drawn. The granularmaterial is shown as supported in a pan above a furnace 28 which may beheated by any suitable means such as an oil or gas burner 29. Thepassage of the wire through this heated granular material serves toevaporate quickly any moisture remaining on the coated wire and whilethe wire is buried in the granular material. In this way the wire can bethoroughly dried without any appreciable oxidizing efiect.

50 indicates a reel on which the straightened and plated wire may bewound.

With the above method the wire is first straightened and then ismaintained in a straight condition during the plating operation so thatas the wire comes from the plating operation it is in its straightcondition with a plating or coating which has not been injured by thestraightening process.

In Fig. 4 I have'shown a different way of subjecting the wire to theaction of the plating bath while the wire is maintained in a straightcondition. In this embodiment the plating material is contained in atank situated above the wire and this tank has one or more dischargeports 31 in its bottom through which streams 32 of plating materialgravitate. The wire while maintained in a straight condition is passedbeneath these discharge ports and through the streams of platingmaterial and is thereby subjected to the plating action.

In this construction I have shown a collecting tank 33 into which thejets or streams 32 of plating material are collected and the platingmaterial may be pumped from the collecting tank 33 back into the tank 30through the medium of a pump 34 which is connected to the tanks throughsuitable pipes 35, 36.

In this embodiment of the invention also the washing of the wir is shownas being done by gravitating jets or streams of water 37 which may bedelivered from nozzles 38 that are connectedto a suitable water supplypipe 39. The wire while still in a straight condition passes through thewater jets 37 and thus becomes properly washed. 40 indicates collectingtanks situated underneath the jets to collect the water delivered fromthe jets.

In both embodiments of the invention the liquid plating material isprojected upon the wire in a flowing stream or jet which serves to applythe plating material thoroughly to all the surface of the wire and toremove any particles of foreign matter which may have adhered to thewire. It also prevents the possibility of improper plating of the wirewhich might be caused by entrainment of wire bubbles by the wire as itis passed through a liquid bath of plating material as in previous knownconstructions. In short, the present method ensures the complete coatingof the wire while in straightened condition and avoids damage to thecoating by subsequent straightening of the wireas heretofore pointedout.

In both embodiments of the invention the wire is first straightened andthen it is subjected to the plating operation while it is still held inthe straight condition. In other words, the wire is maintained in astraight condition during the plating operation.

As stated above the invention is not limited in its use to anyparticular kind of plating material but may be used in connection withthe plating of wire by any suitable liquid plating material.

I claim:

The process of treating wire which consists in passing wire throimh astraightening machine by which the wire is straightened and thenimmediately passing the wire while still in a. straightened conditionthrough an upwardlydirected fountain of plating material.

CHARLES D. JOHNSON.

